Objective: Arterial switch operation (ASO) is the procedure of choice for the repair of simple d-transposition of the great arteries (TGA) during the neonatal period. Beyond this time such correction is performed in two stages. The first step incorporates banding of the pulmonary artery with or without a Blalock-Taussig shunt to train the left ventricle (LV). The second step consists of the ASO. To find out whether candidates for a two-stage procedure would tolerate a one-stage correction, a trial of pulmonary artery banding was performed.
Material and methods: Between February 1986 and December 1995, 224 patients less than 3 months of age with TGA, intact ventricular septum or a small restrictive ventricular septal defect, had an ASO. Seven patients were 4 weeks of age or older (28-70 days). Two of these had a pulmonary artery to systemic pressure ratio higher than 0.6 and underwent primary ASO without complications. The remaining five patients had low left ventricular pressure with a pulmonary to systemic pressure ratio of 0.2-0.5; echocardiography showed a banana-shaped LV with left ventricular wall thickness as low as 3 mm. They underwent a trial of pulmonary artery banding to systemic pressure for 15-30 min. As this increase in workload was tolerated well with an anticipated decrease of oxygen saturation but without hemodynamic disturbances anticipated, the ASO was performed immediately.
Results: Postoperative course was uneventful in all five patients, although catecholamine dependence was prolonged and three patients received enoximone. There were no severe complications. Echocardiography showed an increase in posterior wall thickness from 3 to 6 mm after 19 days in one infant.
Conclusion: Some of the children, assigned for a 'two-stage' ASO may tolerate a primary anatomic repair up to an age of at least three months. This subgroup can be selected by a trial of pulmonary artery banding.